### Installing Payu Node SDK

Source: https://github.com/payu-india/payu-sdk-node/blob/main/README.md

Provides commands to install the Payu Node.js SDK using npm or yarn package managers.

```Shell
npm install payu-sdk
```

```Shell
yarn add payu-sdk
```

--------------------------------

### Initializing Payu Node SDK in Node.js

Source: https://github.com/payu-india/payu-sdk-node/blob/main/README.md

Demonstrates how to initialize the Payu Node.js SDK by requiring the package and providing the Payu key and salt. It notes that the salt should be kept server-side and recommends using environment variables.

```JavaScript
const payu = require('payu-sdk')({
  key: '<payu_key>',
  salt:  '<payu_salt>', // should be on server side only
});
```

--------------------------------

### Generating Hash with Payu Node SDK in Node.js

Source: https://github.com/payu-india/payu-sdk-node/blob/main/README.md

Shows how to use the payu.hasher.generateHash method to create a hash for a transaction, using required transaction details like ID, amount, product info, first name, and email.

```JavaScript
const hash = payu.hasher.generateHash({
  txnid: '20201223',
  amount: '1000',
  productinfo: 'iPhone',
  firstname: 'Ashish',
  email: 'ashish.25@mailinator.com',
});
```

--------------------------------

### Validating Reverse Hash with Payu Node SDK in Node.js

Source: https://github.com/payu-india/payu-sdk-node/blob/main/README.md

Illustrates how to validate the hash received from Payu after a checkout process using the payu.hasher.validateHash method. It requires the received hash, transaction details, and the transaction status.

```JavaScript
const reverseHash = '<payu_hash>' // hash received after payment from payu
const txnStatus = '<payu_txn_status>' // status received after payment from payu
const isValidHash = payu.hasher.validateHash(reverseHash, {
  txnid: '20201223',
  amount: '1000',
  productinfo: 'iPhone',
  firstname: 'Ashish',
  email: 'ashish.25@mailinator.com',
  status: txnStatus,
})
```

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